In Muracle galaxy, a galaxy formed with 10 planets including O2 Planet, the music-loving residences were having happy moments. But as the unwelcomed neighbors from Zuracle galaxy started to spread the unknown organism called 'Ohm', an ominous atmosphere starts to prevail...There is only one way to save the residences of the Muracle Galaxy who are suffering under languidness because of 'Ohm': Increasing oxygen level by performing passionately with the oxygen-creating robot from O2 planet, O2mo!Shall we start the performance of the musical warriors to save the Muracle Galaxy? Let's play!

Features:- O2jam is the world's first online rhythm action game, the first to embody the online music game.-O2jam is for Everyone, meaning anyone can enjoy.- O2jam is good for relieving stress, since the users can have fun by playing the music and feel the beat through tapping keyboard.- Gold-label includes the best songs, Blue-label is made up with popular songs, Black label lets the users to feel the strong beat, Silver label supports various genres including traditional classics- approximately 400 songs are currently under service, categorized based on individuals' preferences.- O2jam is the first online rhythm action game that supports 3-key mode, which makes it to be the leader of popularization of rhythm action games.